Latching device



July 3, 1934. G. H. EDWARDS LATCHING DEVICE Filed Aug. 12, 1933 INVENTOR Patented July 3, 1934 UNITED STATES PATENT OFFICE 8 Claims.

This invention relates to latching devices and more particularly to latching devices for locking closures such as doors.

Objects of this invention are to obtain a tight engagement of the locking members of a latch to produce a smoother locking action. A related object is to prevent rattling of a door or its lock when subjected to vibratory forces or shocks.

In accordance with this invention, there is employed in a latching device a rotatable latching member and a keeper means for retaining this latching member in the latching position. The keeper member is preferably fastened to a jamb to which a closure is to be locked and the latching member to the closure itself, although the arrangement may be interchanged, if desired, that is the latching member associated with the jamb and the keeper with the closure.

A feature of the invention resides in the use of keeper retaining surfaces which are preferably non-parallel with respect to each other. Another feature is that at least one of the retaining surfaces is oblique or non-parallel to the direction the closure moves in closing.

The rotatable latching member, in the preferred embodiment, has a bearing surface which is eccentric with respect to its axis of rotation and engages with the oblique or non-parallel retaining surface of the keeper. Means is provided for causing the rotatable latching member to rotate in one direction to permit latching; and means is also provided for producing a continual tendency for the latching member to rotate in the opposite direction, thus producing the tendency toward tighter latching engagement.

By reason of the eccentric bearing surface of the rotatable latching member, there is a continual tendency toward tighter locking, particu larly when subjected to shocks and vibration, and wear of the locking parts is readily compensated for.

The type of latching action according to this invention is obtained when the said bearing surface of the latching member and the oblique or non-parallel retaining surface of the keeper are so related to each other that the perpendicular to the said retaining surface at its point of contact with the said bearing surface passes behind the axis of rotation of the bearing surface, with respect to the direction the said axis moves (relative to the retaining surface) when moving toward the latched position.

The latch according to this invention is an improvement upon that described and claimed in my United States Letters Patent 1,891,224 issued December 20, 1932.

In the drawing, Fig. 1 is a horizontal sectional view of a latching device in accordance with this invention attached to a door and the associated door jamb, the section being taken at line 1-1 of Fig. 4;

Fig. 2 is a transverse vertical sectional view taken at line 2-2 of Fig. 1;

Fig. 3 is a view'somewhat similar to Fig. 2, but shows the door just prior to being closed at the door jamb; and

Fig. 4 is a longitudinal vertical sectional view taken at line 4-4 of Fig. 1.

Referring to the drawing there is illustrated a" portion of a door, or a closure 10, which in this case is adapted to swing upon a vertical axis, and the associated door jamb 11 for receiving the door when in the closed position. In Figs. 1, 2, and 4 the door and jamb are illustrated in the latched position. The latching device is assembled upon the door and jamb in the manner presently to be described. The locking edge of the door has built thereon a casing composed of plates 12 and 13 of suitable metal. These plates are properly joined at an angle asshown so that the casing is formed upon the abutting end as well as upon the inside wall of the door. The casing may be held together by suitable rivets and attached to the door by screws, as shown. Fastened within the front, or abutting portion, of the easing and rotatable upon a pin 14 is a latch member 15 in the form of a cam having a latching, or bearing surface 16 which is eccentric with respect to the axisof rotation, which is the pin 14.

There is provided a spring 17 having one end engaged against a lug 18 to the casing, and the other end to one side of the rotatable cam, as shown, thereby tending to rotate the cam in a clockwise direction (with respect to Figs. 2 and 3) and hence when not engaged with the keeper of the door jamb the cam is held by the spring action against a stopping member 19 attached to the casing.

The end of the door jamb in juxtaposition with the latching member of the door is cut away somewhat to receive a keeper plate 20 having upper and lower retaining surfaces 21 and 22, respectively, adapted to engage with the rotatable latching cam and with the under edge of the latch 105 casing, respectively.

In moving to the latching position upon closing the door, the inside lower edge of the latch casing at 23 strikes the outer end of the horizontal keeper retaining surface 22, this outer end being curved 110 or cammed downwardly at 24 to facilitate this action. At practically the same time the forward edge at 25 of the rotatable cam strikes the outer end 21 of the oblique upper keeper surface, this latter end being curved or cammed upwardly at 26 to facilitate the engagement. This is shown in Fig. 3 where the latching members attached to the door are shown just beginning to engage with the keeper portion attached to the jamb.

As the door continues to move toward the latched position, the cam is rotated counterclockwise against the force of the spring in the direction shown by the curved arrow on the cam in Fig. 3. This counterclockwise rotation continues until the cam has moved under the cammed portion 26 of keeper surface 21, whereupon it begins to gradually move clockwise under the force of the spring as the door continues to move closed. This clockwise motion is due to the obliqueness of surface 21, this being oblique in the upward direction toward the latched position. At the same time the lower edge of the latch casing slides along the horizontal retaining surface 22 of the keeper, this lower edge thus forming an engaging surface of the latch portion. The rotatable cam finally assumes the position shown in Fig. 2 when the door is completely closed against the door jamb. There are preferably provided resilient buffers 27 and 28 particularly for automobile doors against which the door closes. Since the oblique retaining surface 21 extends somewhat behind the cam 15 with respect to the direction the cam moves when locking the door, a secure latching is obtained.

By reason of the eccentricity of the bearing surface 16 of the rotatable cam, and the fact that the greatest radius of curvature exists at the outer portion thereof (remote from edge 25) there is a continual tendency toward tighter latching against the buffers and also in a vertical direction against the keeper retaining surfaces 21 and 22. This tight latching is augmented'under shocks and vibratory forces such as those to which automobile doors are subjected.

It is seen from an inspection of the drawing that the perpendicular to the upper retaining or engaging surface 21 at the point of contact with the bearing surface 16 of the rotatable latching member passes behind the axis of rotation 14 of the latching member, with respect to the direction of motion of the axis relative to the keeper, when moving toward the latched position.

It is observed that any wear of parts is readily compensated for by the rotation of the cam, or latching member, so that a tight latching action is always obtained in spite of such wear. It is also observed that the locking occurs between the rubber buffers and the retaining surfaces of the keeper; hence no additional auxiliary devices such as dovetails, are required.

To enable the latching device to be released to permit opening of the door a releasing, or retracting, mechanism is employed which is operable by handles 29 and 30 on either side of the door. The handles operate shaft 31 which extends transversely through the door directly behind the latch- I ing mechanism. The shaft has fastened thereon a lifting arm 32 the arm of which extends in a forward direction just under a downwardly abutting arm 33 of the cam 15. A stop 34 attached to the casing prevents the arm 32 from dropping downwardly.

When either of the handles is pushed down wardly so that the shaft 31 is turned in a clockwise direction (with reference to Fig. 4) the lifting arm 32 strikes the abutting arm 33 of the cam thereby rotating the cam in the counterclockwise direction, thus disengaging it from the upper oblique keeper surface 21 so that the door may be readily moved open.

I claim:

1. A look for latching a closure member to a jamb member comprising a rotatable latching means having a bearing surface, attached to one of said members, and means for producing a continual tendency of said latching means to rotate in one direction, the other of said members comprising a keeper means having a retaining surface which is non-parallel to the direction said closure moves in closing, the arrangement being such that the bearing surface of said rotatable latching means engages with said non-parallel retaining surface and rotates as the latching position is approached, said bearing and retaining surfaces being so related to each other that the perpendicular to said retaining surfaces at its point of contact with said bearing surface lies behind the axis of rotation of said latching means, with respect to the direction said axis moves when moving toward the latched position, whereby a tight latching action is obtained.

2. A latch for latching a door member to a jamb member comprising a keeper attached to one of said members and a rotatable latching cam attached to the other of said members, said keeper having a retaining surface for engaging said cam, said retaining surface extending obliquelyaway from said cam with respect to the direction of relative motion of said cam in moving toward the latched position, said cam having a bearing surface which is eccentric with respect to its axis of rotation, the greatest radius of curvature being at the end of said bearing surface which is remote from the direction of motion of said axis, relative.to said keeper, in moving toward the latched position, and means for producing a continual tendency for said cam to rotate in the latching direction, whereby when said cam is in engagement with said retaining surface said cam rotates as said door continues to move toward the latching position, said cam being free to rotate into a tightly latched position whenever the latching tends to become loose, as by wear of parts or vibration.

3. An arrangement for latching a door member to a jamb member comprising an engaging surface and a rotatable latching cam attached to one of said members and a pair of retaining surfaces attached to the other of said members, a first of said retaining surfaces receding obliquely away from said cam with respect to the direction of motion of said cam relative to said retaining surfaces, in moving toward the latched position, said first retaining surface being adapted to engage with a bearing surface of said cam, and the other retaining surface being adapted to engage with said engaging surface, the bearing surface of said cam being eccentric with respect to its axis of rotation, and means for producing a continual tendency for said cam to rotate in the direction which causes said cam to remain in close engagement with said receding retaining surface while said engaging surface is in engagement with said other retaining surface, whereby a tight latching engagement is maintained in spite of vibration or wear of parts.

4. A latch for latching a door to a jamb comprising a latching portion abutting from said door and a keeper portion attached to said jamb, said latching portion comprising a rotatable latching cam having a bearing surface eccentric with respect to its axis of rotation and an engaging surface substantially parallel to the direction said door moves in closing, said keeper portion comprising a pair of retaining surfaces one of which is oblique and engages with said cam and the other of which is parallel with and engages with said engaging surface, and means for producing a continual tendency for said cam to rotate, whereby upon closing said door said cam strikes the outer end of said oblique surface and is thereby rotated in the direction opposite that due to said continual tendency, but upon further closing of said door said bearing surface engages said oblique surface and said cam rotates in the direction due to said continual tendency, said bearing and oblique surfaces being so related to each other that the perpendicular to said oblique surface at its point of contact with said bearing surface lies behind the axis of rotation of said cam, with respect to the direction said axis moves when moving toward the latched position, whereby tight latching is obtained by reason of said oblique surface lying obliquely beyond said card with respect to the direction said door moves in opening.

5. An arrangement for locking a door member to a jamb member, comprising a pair of retaining surfaces attached to one of said members and means comprising a rotatable cam attached to the other of said members, said means being securely held between said retaining surfaces when in the latched position, said cam having a bearing surface in latching contact with one of said retaining surfaces, said latter retaining surface receding obliquely away from said cam with respect to the path of motion of said cam in moving toward the latched position, said bearing surface being eccentric with respect to its axis of rotation, and means for producing a continual tendency for said cam to rotate in the direction which maintains said bearing surface in tight engagement with said oblique surface, in spite of wear of parts, or vibration.

6. An arrangement for looking a door member to a jamb member, comprising a pair of retain ing surfaces attached to said jamb member, and means comprising a rotatable cam and an engaging surface attached to said door member, said means being securely held between said retaining surfaces when in the latched position, said cam having a bearing surface in latching contact with one of said retaining surfaces, said latter retaining surface receding obliquely away from said cam with respect to the path of motion of said cam in moving toward the latched position, said bearing surface having non-uniform distances to its axis of rotation, the greatest distance being at the end of said bearing surface remote from said jambwhen the door is open, and means for producing a continual tendency of said cam to rotate in the general direction of said receding surface, whereby a tight latching engagement of said means is maintained between said retaining surfaces, in spite of vibratory shocks or wear of parts.

7. An arrangement for lockinga door member to a jamb member against resilient buffers, comprising a rotatable cam and an engaging surface attached to one of said members, said cam and engaging surface being securely held between a pair of retaining surfaces attached to the other of said members when in the latched position, said cam having a bearing surface in latching contact with one of said retaining surfaces, said latter retaining surface receding obliquely away from said cam with respect to path of motion of said cam in moving toward the latched position, said bearing surface having non-uniform distances to its axis of rotation, the greatest distance being at the end of said bearing surface remote from said other member when the door member is open, and means for producing a continual tendency for said cam to rotate in the general direction of said receding surface, whereby a tight latching engagement is maintained against said buffers, in spite of vibratory shocks or wear of parts.

8. An arrangement for looking a door member to a jamb member,'comprising a pair of retaining surfaces attached to one of said members and means comprising a rotatable cam attached to the other of said members, said means being securely held between said retaining surfaces when in the latched position, said cam having a bearing surface in latching contact with one of said retaining surfaces, said latter retaining surface extending obliquely behind said cam when in the latched position, with respect to the path of motion of said cam in moving into the latched position, means producing a continual tendency of said cam to rotate in one direction, said bearing and retaining surfaces being so related to each other that the perpendicular to said retaining surface at its point of contact with said bearing surface lies behind the axis of rotation of said cam, with respect to the direction said axis moves in moving toward the latched position, whereby a tight latching engagement is obtained in spite of vibration or wear of parts.

GEORGE H. EDWARDS. 

